The present invention relates generally to the monitoring of a process involving a plurality of parameters, and more particularly to a method of effecting such monitoring and an apparatus for carrying out the method.
The art already knows of arrangements for automatically monitoring processes involving a plurality of parameters. For instance, it is known to automatically regulate temperatures or liquid levels or the like. It is also known to monitor the operation of machines of various types. Such monitoring involves little or no difficulties when the surveillance problem involved is restricted to monitoring the deviation of a parameter which can vary between two fixed values. An example of this would be if a temperature range is being monitored and it must be detected whether the temperature falls below a minimum permissible temperature at the lower end of the range, or exceeds the maximum permissible temperature at the upper end of the range. The same can be said, by way of example, of monitoring a pressure.
However, when the permissible range of magnitude of a parameter is not constant, or when the character of the magnitude is not constant, but instead is a function of one or more other parameters -- such as time --, the problem becomes much more complicated. Where monitoring problems of this type were heretofore involved, the prior art required very complicated equipment, which had to be the more elaborate the more flexible the operation of the equipment was required to be, for instance if the equipment was required to be adjustable so that is could be programmed according to different functional relationships between various parameters.